Sorry for reviving an old thread, but this is directly related to the setup that you helped me out so much with before. It seems I overlooked one aspect of the setup that doesn't seem to be working. We've established that when I user goes to:

test.sites.example.com/cms/

they are redirected to a static location (shared code) directly to the index.php file:
/usr/local/staff/code/cms/index.php

The problem I'm noticing now is that it seems like Apache is not by default using DirectoryIndex settings for normal directories in the users docroot.

I actually don't want a directory index (listing of files) i just want it to execute the index.php, or any other file I have listed in the DirectoryIndex directive. If I specify index.php at the end of the URL, it seems to call it, but then comes back with the same 403 error, as if somewhere in the code it's trying to refer to itself without the statically specificaly index.php at the end. (it shouldn't have to).

Basically, any files/directories the user puts in their docroot i want to behave like normal... ie. if they end a URL in a directory name, the index file is executed, etc.

richardk wrote:So you only want to apply the RewriteRules to the files/directories from the AliasMatches.

Not exactly, I'm assuming there still needs to be some RewriteRules in order to place the user in the correct base directory (ie. the document root for test.sites.example.com would be /data/sites/sites.example.com/htdocs/clients/test)